The present invention relates to a valve timing control apparatus for an internal combustion engine which variably controls timings of opening and closing an engine valve (i.e., an intake valve and an exhaust valve) during an engine operation.
Japanese Patent Application Unexamined Publication No. 2005-325749 discloses a valve timing control apparatus that includes a housing constituted of a housing body and a front plate, a vane rotor and a torsion spring installed between the housing and the vane rotor. With the provision of the torsion spring, a biasing force of the torsion spring acts on the vane rotor to move against a reaction force of a valve spring (a force to retard a rotational phase of a camshaft) which is generated upon an opening operation and a closing operation of an engine valve. As a result, the valve timing control apparatus can be enhanced in operating performance and response performance.